#include <bits/stdc++.h>


using namespace std;

template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) { os << '{'; string sep; for (const T &x : v) os << sep << x, sep = ", "; return os << '}'; }
 void dbg_out() { cerr << endl; }
template<typename Head, typename... Tail> void dbg_out(Head H, Tail... T) { cerr << ' ' << H; dbg_out(T...); }
#ifdef ONPC
  #define deb(...) cerr << '[' << __FILE__ << ':' << __LINE__ << "] (" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__)
#else
  #pragma GCC optimize("O3,unroll-loops")
  #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
  #define deb(...)
#endif

// c++ short types
#define vt vector
//typedef long long ll;
typedef long double ld;

void whattime() { cout << "finished in " << clock() * 1.0 / CLOCKS_PER_SEC << " sec" << endl; }
// const int mod = 1e9 + 7;
const int mod = 998244353;
const int inf = 1e9;
const int64_t infll = 1e13;
bool debug = false;
const ld eps = 1e-9;
const ld pi = acos(-1);
mt19937_64 rng((int) chrono::steady_clock::now().time_since_epoch().count());

void solve() {
  int n; cin >> n;
  vt<vt<int>> g(n);
  for(int i = 0; i < n; ++i) {
    int p; cin >> p;
    --p;
    if(i) {
      g[p].push_back(i);
    }
  }
  vt<int> res(n, 1);
  for(int i = n-1; i >= 0; --i) if(not g[i].empty()) {
    auto &v = g[i];
    sort(v.begin(), v.end(), [&](int a, int b) -> bool {
        return make_pair(res[a], a) > make_pair(res[b], b);
    });
    res[i] = res[v[0]];
    if(v.size() > 1) {
      res[i] = max(res[i], res[v[1]] + 1);
    }
  }
  cout << res[0] << '\n';
}

int main()
{
	ios::sync_with_stdio(false); cin.tie(nullptr);

	int tt = 1;;
	if(debug) {
		tt = 1e3;
	} else {
		cin >> tt;
	}

	for(int t = 0; t < tt; ++t) {
		solve();
	}
	
#ifdef ONPC
	whattime();
#endif
	
	return 0;
}